Apparatus for heating hard water



May 15; 1945. E, w, WE P 2,376,298

APPARATUS FOR HEATING HARD WATER Original Filed March 21, 1940 INVENTOR BY lZZzz/a/d W Wip, I

Patented May 15, 1945 APPARATUS FOR HEATING HARD WATER Edward W. Welp, Chicago, Ill., assignor to Graver Tank & Mtg. 00., Inc., Catasauqua, Pa., a corporation of Delaware Continuation of application Serial No. 325,115,

March 21, 1940. This application Serial No. 444,051

9 Claims. 01.

This invention relates to an apparatus for heating hard water by steam. It has more particular reference to a hot process water softener having improved means for preheating the water in a restricted chamber to eliminate scale forming impurities. This latter application will be described for purposes of illustration but the invention is not to be limited thereby.

It is an object of this invention to provide a I novel apparatus for preheating water of high bicarbonate hardness and which will eliminate the possibility of scale formation on the walls of the preheating vessel.

Another object is so to control the flow of water and steam as to reduce or eliminate the possibility of scale formation on the walls of the heating vessel.

Another object resides in the provision of a preheater having an improved jet for combining steam and water and means for discharging the water as a relatively thin, rapid, integral stream, said stream being subjected to the heating action of high temperature steam in surrounding relation therewith.

Still other objects may appear from the. following disclosure.

May 22, 1942,

. vention supports a cone so that the water issues as a relatively thin stream which is distributed over the surface of the cone to provide the greatest degree of contact between the water and the high temperature steam admitted to the preheater by the steam inlet l3.

Referring more particularly to, Figure 3, the

nozzle ll having a restricted opening l8 and the In the drawing, Figure l is a vertical sectional view showing a hot process water softener embodying the features of the invention;

Figure 2 is a top plan view of the improved nozzle and divider cone of the invention;

Figure 3 is a vertical sectional view of the nozzle and divider cone showing the arrangement of the several parts; and

Figure 4 is a horizontal sectional view taken substantially along line 4| of Figure 3.

The embodiment of the invention illustrated in the drawings comprises the preheater compartment of a softener tank I0 having a member ll providing a top closure for the tank, a removable door 12 in the nature of an inspection door so that access may be had to the interior for purposes of repair and the like, and a steam inlet l3 located on the side of the tank oppos te the inspection door I2. An interior bafi'le I4 is 10- threaded portion I3 is adapted to be secured to the depending end of pipe l5 by the collar 20 so that in effect said nozzle forms a continuation of the water inlet pipe. Vanes 2| are suitably welded at 22 to the exterior of the nozzle to provide a support for the Venturi-shaped steam jet 23 and a support for the cone 24. The steam jet along portion 25 has a gradually decreasing diameter in a downward direction until the restricted throat 2B is reached, whereupon the skirt 21 flares outwardly. Along the upper interior surfaces of portion 25 the steam jet is suitablywelcled as at 28 to the vanes 2| and said vanes also have welded thereto at 29 the cone 24 which is concentric with the steam jet 23 and with the nozzle I! having its pointed end indicated by numeral 30 extending within the opening it of the said nozzle.

It will be noted that I provide a body or reservoir of heated water, a superposed body of steam, and a wall structure confining both bodies. The assembly of the nozzle, cone, and Venturi member is so constructed, installed, and operated that the conical sheet of water, 3|, which is discharged from this assembly, falls upon the surface 32 of the body of heated water 33 which is accumulated in the tank, at points spaced from the wall 36 which confines this body of Water.

It will be understood that the'hard water which enters the tank Ill through the pipe I5 may have been dosed with lime, soda, phosphate or the like; or such dosage may follow later. In some instances, chemical treatment can be dispensed with altogether.

cated adjacent the steam inlet for directing the steam toward the upper portion of the tank.

The pipe l5, extending within the tank to sub,- stantlally the center thereof. continuously supplies cold water for treatment to, the preheater of the invention. Said pipe is suitably supported from the cylindrical wall of the tank by having threaded connection w th the boss I6. Water from the pipe I5 is discharged into the preheater by a nozzle which in accordance with the in- In earlier apparatus, the water has been dis charged ,into the heating chamber in form of a spray impinging on the walls of the chamber. Thus there has been contact between the water in which the incipient chemical or thermal softening reactions take place, and the walls of the heating chamber. Such contact, when continued over some period of time, with a water containing a large amount of bicarbonate hardness. causes a heavy scale to be formed on the walls of the heating chamber. Actually, such scale is formed at least as fast as in a steam boiler suppl e with hard feed water.

The formation of scale in the heater is objectionable for at least some of the reasons which apply in case of steam boilers. Among other things, this growth of scale, when unchecked, will ultimately restrict" the treatment space in the heater chamber to the point where proper heat treatment is no longer possible. more, such scale formations tend to disintegrate or break off; and the scale, or parts thereof, will then drop into the sludge sump, upsetting the water in the clarification chamber, and clogging the sludge pipes and pumps. Therefore it has been necessary with prior art apparatus to interrupt the operation at frequent intervals for scale removal and repairs. Such frequent shutdowns are expensive and objectionable. All those difllculties arev overcome, or at least materially reduced, by apparatus constructed according to this invention.

The nozzle assembly of this invention is preferably symmetrical in. itself. In the embodiment shown this nozzle assembly is installed in the center of the tank. The nozzle assembly, and particularly its outwardly flaring discharge or end section 21 is so constructed that during proper operation thereof, a thin and smooth, not atomized stream of water issues therefrom and strikes the water surface 32. This stream should not strike the wall 34. For this purpose, the nozzle assembly is installed at such elevation, and the wall of said end section 21 has such flare and is so constructed on the inside thereof that, when its flare is continued downwardly by straight imaginary lines, it fails to reach or intersect the wall 34, but reaches and intersects the water surface 32 at points spaced from said wall. The

stream of water which issues from the nozzle assembly substantially follows said imaginary lines. It flows down as a thin, smooth sheet forming a hollow cone, flowing rapidly near the apex so as to prevent the deposition of scale in the passage of the nozzle assembly, and avoiding the ,wall 34 so as toprevent the formation of scale on this wall.

The steam which enters the preheating chamber is upwardly deflected by the interior baille l4 adjacent the steam inlet. It is then drawn into the nozzle assembly by the jet or injector action of 'the water issuing, from the nozzle lBu In advance of the restricted diameter 26 and also beyond the same the high temperature steam and the relatively thin stream of water surrounding the cone are brought into intimate relation so that the greatest possible quantity of heat is transferred to the water to materially raise its temperature. Th steam is caused to travel along as a result of the jet action of the member 23. In fact, although the high temperature steam is admitted at the upper end of the tank and. positively directed to the upper portion of the tank by baflie means the flow of the steam will be in a downward direction within the tank because of the action of said jet as described. A double heating action is thereby given Furtherand flow together on the way down to the water lever 32. It is this heating of the water, with or without chemical treatment, which causes the separation of scale materials. As soon as the temperature of the water reaches a certain degree,'the half-bound carbon dioxide (CO2) of the calcium bicarbonate (CaCOaHzCOs) is driven off, and the remaining substance precipitated in form of crystals of the calcium monocarbonate (CaCOa), with liberation of water (H2O). In the case of magnesium bicarbonate (MgCOsHzCOa) two molecules of carbon dioxide (2002) are similarly removed, and magnesium hydroxide (Mg(OH) 2) precipitated. The reaction is effected with improved success, and possibly increased velocity, if chemicals such as lime (Ca(OH)'z) and soda (NazCOa) are added to the Water. The formation of calcium carbonate and" magnesium hydroxide is a crystallizing process. While all of this process has not been elucidated as yet, it appears that the results are largely dependent on the conditions under which precipitation is started, and the surroundings in which initial. crystals are formed. If th crystalsare initially precipitated in contact with solid bodies they tend to attach themselves to such bodies individually, and to' cling to the same most firmly. Otherwise, they attach themselves to one another, forming fiocculent partic1es, -t he sum total of which appears as a soft sludge and has little adhesive tendency. If the nascent crystals are precipitated in contact with th wall 34, they tend to there is merely contact between said wall and formed, fiocculent particles of sludge, there is no such tendency, or at least it is not nearly so strong. This may explain the fact, which certainly is established by experience, that it is more objectionable to have contact between the water being heated and the wall, than between the heated water and the wall.

For this and otherreasons it is desirable to heat the incoming water so quickly as may be possible within economical limits. The thin and uniform stream of water which is caused and enforced by the nozzle assembly is an ideal medium for such intensified and rapid heat reaction. Furthermore it is important to have intimate and prolonged contact of the water with the steam, wihch is insured by the method of causing contact or admixture of the two fluids in the nozzle assembly as described,

Some of the steammay be condensed as it loses heat to the water. This condensate follows the same conical, downward path that is established for the water under treatment. The uncondensed steam which forms ,part of the mixture issuing from the nozzle assembly, may have some tendency to expand laterally and to entrain small drops of water; In addition, there is a slight chance for disturbance as the flowing water falls on the water surface. Thus the downwardly flowing cone of water, or parts thereof. may be enveloped by a fine mist or spray filling a zone of conical shape or approximately so, and of greater diameter at some points than the firstmentioned cone of water 3|. Such an enveloping mist or spray would be detrimental if it were allowed to expand unduly. It would then cause water being heated to reach the wall 34 and to trickle down. Such contact of the wall with form a hard and objectionable scale thereon. If

adhering to the-wall. However, only a minimum tion is aided by the aforementioned baiiie l4 which guides'the incoming steam upwardly, "preventing lateral crosscurrents. Furthermore, the

pressure within the hollow cone of flowing water 1 3i will be low, and steam will be drawn into this hollow space, causing a convergent rather than a divergent and expanding flow of the steam.

A part of the steam which is discharged downwardly from the nozzle assembly returns upwardly along the wall 34. Little, if any, harm can be done by that flow, since the velocity thereof is too small to'support water drops of appreciable size, and the water carried thereby'has already been heated to a large extent, completing the floc-forming reactions. I

The arrangement, proportions, and dimensions as shown and described are subject to considerable modifications, the present disclosure being intended to illustrate but not to limit the invention, and various modifications being obvious to persons skilled in this art, upon a study of this disclosure.

This is a continuation of my application No.

325,115 filed March 21, 1940.

I claim: 4

1. In apparatus for heating water to remove scale-forming impurities, in combination, a tank having a reservoir in the base thereof and an inlet above the reservoir for a fluid heating medium,

a nozzle in the upper end of the tank for discharging water .to be heated toward the reservoir, a conical member depending from said nozzle and positioned with the apex toward the nozzle to divide the water issuing therefrom into a relatively thin stream of annular shapeby causing the water to flow along th exterior surface of the conical member, and Venturi means concentrically disposed in surrounding relation with the conical member, said Venturi means having open ends and providing a restricted throat inter mediate its length, whereby the fluid beating medium is caused to flow through said Venturi means in the same direction as the stream and is relatively thin stream flowing along the exterior surface of the conical member to raise the temrelatively thin stream of annular shape by causing the water to flow along the exterior surface of the conical member, Venturi means concentrically disposed in surrounding relation with the conical member, said means having an inlet at its upper'end and an outlet at its lower end adjacent the discharge of the stream from the conical member, and a restricted throatprovided by said Venturi means intermediate the inlet and outlet ends thereof, whereby the fluid heating medium, is caused to flow through said Venturi means in the direction of the stream and is simultaneously confined in close proximity to the relatively thin stream flowing along the exterior surface of the conical member to raise the temperature of the water.

3. In apparatus of the character described, a nozzle for discharging the liquid to be'treated, a plurality of supporting vanes extending radially from the nozzle and depending below the discharge end thereof, a conical member located below the nozzle and positioned with its apex directed toward and centrally of said nozzle, whereby the liquid issuing from the nozzle is caused to flow along the exterior surface of the conical member as a thin stream of annular shape, said conical member having contact with the depending ends of the vanes and being secured in position by said vanes, Venturi means supported by said vanes in surrounding relation with the coni-\ cal member, both ends of said Venturi means being open and said means providing a restricted passage intermediate the open ends and in close proximity to the discharge of the stream from the conical member.

4. In apparatus of the character described, a tank, a nozzle in said tank for discharging water to be treated, a conical member associated with said nozzle with its apex directed toward the nozzle for dividing the water issuing therefrom into a relatively thin stream of annular shape by causing the water to flow along the exterior sur-l face of the conical member, Venturi means con-i centrically disposed with respect to the nozzle/ and the conical member and surrounding at least those parts of said nozzle and conical member which are adjacent the apex, said Venturi means being open at each end communicate with the interior of the tank and providing a passage between said open ends having a restricted throat in a, plane spaced from said nozzle in the direction of the stream, and steam inlet means in f said tank delivering high temperature steam to simultaneously confined in close proximity to the V said Venturi means at the endopposite the restricted throat, whereby the steam is caused to flow in the same direction as the stream of water and is confined in close proximity to the relatively thin stream flowing along the exterior surface ofthe conical member to thereby raise the temperature of the water.

' 5. In apparatus of the ,character described, a

tank, a water inlet pipe for saidtank, a nozzle assembly within the tank depending from said inlet. pipe, said assembly comprising a nozzle for discharging the liquid to be treated, a plurality of-supportin vanes extendingradially from the nozzle, a conical member located below the noza member having a restricted throat intermediate zle and supported by said vanes with its apex directed toward the nozzle and centrally thereof, a Venturi member of substantially circular crosssection supported in surrounding relation with the nozzle and depending below the same to also encompass the conical member, both ends of said Venturi member being open and said open ends providing an inlet at the upper end and an outlet at the lower end respectively, and said Venturi said inlet and outlet. I l

6. In apparatus for heating wa er to remove scale-forming impurities, in combin ion, a tank adapted to confine a body of heated water and a body of steam above the surface of said water, a steam inlet above said surface, an inlet for hard water to be heated above said surface, said water inlet discharging into said tank through a circular opening, a flow dividing member associated with and adapted at least to partially enter said opening, said flow dividing member having a surface diverging from an apex in the direction of the flow of water fromsaid water inlet, and Venturi means concentrically disposed in surrounding relation with and in close proximity to at least part of said Water inlet and said flow-dividing member, said Venturi means having open ends in said tank and providing a restricted throat intermediate its ends.

7. In apparatus for heating water to remove scale-forming impurities, in combination, a tank adapted to confine a body of heated water and a body of steam above the surface of said water, a steam inlet above said surface, an inlet for hard water to be heated above said surface, a flow dividing member having a surface diverging from an apex and having said apex relatively adjacent said water inlet whereby said member is adapted to cause the water issuing from said water inlet to flow along the surface of said member and to form from the water issuing from said inlet a relatively thin stream diverging from said water inlet, and Venturi means concentrically disposed in close proximity to at least part of said water inlet and said flow-dividing member, said Venturi means having open ends in communication with the interior of the tank and providing a restricted throat intermediate its length, whereby the steam is caused to flow through said Venturi means in the same direction as said stream of water.

8. Apparatus according to claim 7 wherein said Venturi means is spaced from and supported by said fiow dividing member by means of vanes.

9. Apparatus according to claim 7 wherein said steam inlet has associated therewith a flow guiding member adapted to direct the steam towards a part of said tank relatively adjacent said apex of said flow dividing member.

EDWARD W. WELP. 

